This program project grant (PPG) builds on an innovative strategy for AIDS vaccine development that takes advantage of the ability of recombinant rhesus CMV (RhCMV) vectors expressing SIV antigens to elicit long- lived, tissue-based effector memory T cell responses that are associated with localized and very early control of virus replication. The PPG brings together experienced investigators that provide complementary expertise in their projects with the common goals of designing, constructing and testing next generation RhCMV/SIV vaccine vectors with enhanced efficacy and safety. Core D will play a key role in supporting these efforts and integrating the different projects by the provision of standardized virology and immunology services and assays. Specifically, Core D will support the project-specific in vivo studies through production and characterization of recombinant RhCMV/SIV vectors, virus load monitoring, and evaluation of SIV antigen-specific T cell responses. RELEVANCE (See instructions): The HIV/AIDS epidemic constitutes one ofthe most pressing public health threats in the world today, and an effective vaccine is urgently needed. The work proposed in this HIVRAD program will further explore and develop a highly innovative approach to HIV/AIDS vaccine development, exploiting the striking immunogenicity, persistence and genetic malleability of cytomegalovirus (CMV) to design a vaccine vector that elicits long-lived, tissue-based T cell responses that can provide early stringent control of AIDS-causing viruses. The Core lab proposed here (Core D) will provide routine virology and immunology services to this Program, including production of the CMV vaccines and provision of standardized assays for monitoring virus replication and secretion and SIV-specific T cell responses in the rhesus monkey model ofAIDS.